From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 01BCA351C39; Tue, 3 Mar 2026 20:52:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772571150; cv=none; b=X7iGUxgNSJm6OKkDIHKOmUPag2UAheaaXDOQDKSZOxNftgkRGd5imLTfKEbvJ1tL14LC9a6Dw/gYKYRMakCFwY2fZl21mJ3Samv+2IOgP/aHkjIJcTOl9/cp0yiDcBZ1TuCuXyYX/iGy3umkeORFIKvX55OncPy7OU2WPqNtsqQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772571150; c=relaxed/simple; bh=Xeo5EivCSK8i5ewFGXEJ1ysYZsQ7yZF4ov0qH2Wp40A=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=IDsxmtP+vJ0qR+iOVVPy4CKZyDLim889druUosMUTsRWFO1hQslmIXwqX6GPtaBf0JOsYLIx4ZbimBgiDteQQkLYpBw4qpzmBiAbbzyqz0mUOBDnzWoM1OaP96XJGwIa6litXYQcTaSkH+HvqGvb9nZXHbjZ5Web+22lfIiKKCo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YCGoGU5Y; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="YCGoGU5Y" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5CF02C116C6; Tue, 3 Mar 2026 20:52:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772571149; bh=Xeo5EivCSK8i5ewFGXEJ1ysYZsQ7yZF4ov0qH2Wp40A=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YCGoGU5Y39HeDTKSZIz/fjegDB4ezi/z5WfVFuIsI15kReBnn/1bImL6tNTrZugWy zEIdljZz3VdMgP5z4YNVpKFnKfu/fNcryiqk9WOl6obxZrnZ1sB1Ei0rg81L/yr8R8 YNagly2k+91n9w27EUNbivoU8RTsUry5AStbx5KGb5Gqq8ox+7PYNCn/gPJHDVITeE No9E0TTCBHKiNp/RsPqi0WPCGAwxx9+hvnJCPPYfJJO2zvKYbs0zwdH+bXUCT1oxnH /rUMFRrQVnhAkj9X0iY7HoBFvVCdMKJ+mZt7IB3XP/HOMZ15Qqt5Wdl0PwZE0G8f8x a3pWuJ8Me+Kng== Date: Tue, 3 Mar 2026 10:52:28 -1000 From: Tejun Heo To: Johannes Berg Cc: Ben Greear , linux-wireless , "Korenblit, Miriam Rachel" , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: 6.18.13 iwlwifi deadlock allocating cma while work-item is active. Message-ID: References: <18c4bfed-caca-bef3-a139-63d7fa48940a@candelatech.com> <3456b2c89f057900b39ce79ea8ca1154c5014e43.camel@sipsolutions.net> <0de6c8d1-d2fa-44ac-8025-cfcfecd87b02@candelatech.com> <35779061f94c2a55bb58dcd619ae91c618509cf4.camel@sipsolutions.net> Precedence: bulk X-Mailing-List: linux-wireless@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <35779061f94c2a55bb58dcd619ae91c618509cf4.camel@sipsolutions.net> Hello, On Tue, Mar 03, 2026 at 12:49:24PM +0100, Johannes Berg wrote: > Fair. I don't know, I don't think there's anything that even shows that > there's a dependency between the two workqueues and the > "((wq_completion)events_unbound)" and "((wq_completion)events)", and > there would have to be for it to deadlock this way because of that? > > But one is mm_percpu_wq and the other is system_percpu_wq. > > Tejun, does the workqueue code somehow introduce a dependency between > different per-CPU workqueues that's not modelled in lockdep? Hopefully not. Kinda late to the party. Why isn't mm_percpu_wq making forward progress? That should in all circumstances. What's the work item and kworker doing? Thanks. -- tejun